modern science makes conserved knowledge only a means to learning, to discovery. To recur to our illustration. A commanding general cannot base his actions upon either absolute certainty or absolute ignorance. He has a certain amount of information at hand which is, we will assume, reasonably trustworthy. He then infers certain prospective movements, thus assigning meaning to the bare facts of the given situation. His inference is more or less dubious and hypothetical. But he acts upon it. He develops a plan of procedure, a method of dealing with the situation. The consequences which directly follow from his acting this way rather than that test and reveal the worth of his reflections. What he already knows functions and has value in what he learns. But will this account apply in the case of the one in a neutral country who is thoughtfully following as best he can the progress of events? In form, yes, though not of course in content. It is self-evident that his guesses about the future indicated by present facts, guesses by which he attempts to supply meaning to a multitude of disconnected data, cannot be the basis of a method which shall take effect in the campaign. That is not his problem. But in the degree in which he is actively thinking, and not merely passively following the course of events, his tentative inferences will take effect in a method of procedure appropriate to his situation. He will anticipate certain future moves, and will be on the alert to see whether they happen or not. In the degree in which he is intellectually concerned, or thoughtful, he will be actively on the lookout; he will take steps which although they do not affect the campaign, modify in some degree his subsequent actions. Otherwise his later "I told you so" has no intellectual quality at all; it does not mark any testing or verification of prior thinking, but only a coincidence that yields emotional satisfaction--and includes a large factor of self-deception. The case is comparable to that of an astronomer who from given data has been led to foresee (infer) a future eclipse. No matter how great the mathematical probability, the inference is hypothetical--a matter of probability. 1 The hypothesis as to the date and position of the anticipated eclipse becomes the material of forming a method of future conduct. Apparatus is arranged; possibly an expedition is made to some far part of the globe. In any case, some active steps are taken which actually change some physical conditions. And apart from such steps and the consequent modification of the situation, there is no completion of the act of thinking. It remains suspended. Knowledge, already attained knowledge, controls thinking and makes it fruitful.